Multi-station turrets are used on chucking, lathe or other types of machining equipment that can perform turning, facing, boring, threading or other similar machining operations. Such turrets provide a multiple number of tools, one at each station or position that will allow increased production since tools will not have to be changed as frequently. Turrets can be automatically or manually indexed from station to station to sequentially position the next and different tool at the next desired location on a work piece Such turrets are also variously indexable on various types of movable carriage structures. For purposes of this invention, turret operation is assumed to be conventional
With reference to FIGS. 1, 2 and 3, a typical turret is shown together with known types of tool mounting mechanisms. Such tool mounting elements are required since it is still necessary to change tools on a turret. Heretofore, this change from one tool to another, required as much set up time as when the first set of tools was put into place on the turret and then adjusted to the desired position.
A conventional multi-station turret is generally indicated at 10 and is comprised of a turret top plate 12 with a plurality of inverted T-shaped slots 14 which have been milled at a defined angle into the upper part of plate 12 so as to extend upwardly through the upper surface 16. These slots generally take the form of an inverted T so that the inwardly directed flanges created will hold a tool holder 18. In many conventional versions, eight such tool holders can be mounted in position on the turret top plate as tool holders 18 and 30 are in FIG. 1. The two exemplary tool holders 18 and 30 are shown in FIGS. 2 and 3. The tool holder in FIG. 2, shown at 18, is provided with a top portion that includes a through slot 20 for receiving a single tool 26, a recessed portion 22 that will fit between the inwardly directed flanges of the T-slot and an enlarged shoe portion 24 that fits between those flanges as shown. The reduced portion 22 and shoe 24 will slip within slot 14 and as shown in FIG. 1, with tool 26 in place within slot 20 when set screw 28 is screwed down onto tool 26, the latter will be forced into contact with upper surface 16 of the turret top plate 12. Continued downward movement of set screw 28 will force the upper flange surfaces of shoe 24 to mate with the complementary portion of the lower surfaces of the slot 14 flanges. Accordingly, screw 28 simultaneously holds tool 26 in place and locks the tool mounting member 18 in place on the turret top plate 12.
In order to accurately position the tool holder or mounting member 18, set screw 28 would be loosened so that member 18 is slidable horizontally along surface 16 back and forth within the slot until the operator is assured the tool holder is correctly positioned horizontally along the length of slot 14. To adjust the vertical height of the tool, which would otherwise rest on surface 16 of the turret top plate, appropriate shims can be placed beneath tool 26 thereby lifting the tool with respect to surface 16. Once the tool holder is positioned both horizontally and vertically, or once all such tools were positioned at each station, it would be normal for the operator to conduct a trial run to be sure each of the various tools were correctly positioned and that no minor alterations were required. If alterations were needed, they would then be made, to assure the proper positioning of the tool to effect the proper operation before production use started.
FIG. 3 shows a second type of conventional tool holder, 30, for holding a boring tool 32. Rather than having a defined foot, as shown in FIG. 2 at 24, to fit within slot 14, tool holder 30 employs a bolt 34 that has a suitably shaped head 36 designed to fit within slot 14. Boring tool 32 is held in tool holder 30 by means of set screws 38. In order to position tool holder 30 with respect to turret top plate 12, head 36 would be slid into slot 14 and with the holder 30 resting on surface 16 and after appropriate positioning horizontally or with the use of shims to adjust the vertical height of tool holder 30, if necessary, bolt 40 would then be tightened thus securing head 36 within slot 14 and holding holder 30 therebetween.
To remove tool holders 18 or 30, as shown in FIGS. 2 and 3, set screw 28 or nut 40 are loosened, respectively, which will allow the tool holder to be removed. However, once removed, repositioning of another tool or even that same tool holder back into position, would again require repeating the adjustment steps just discussed above together with additional trials by the operator to assure the new or repositioned tool holder was positioned in the desired location, both horizontally and vertically.
To shift to a different tool holder would, of course, require the same sort of initial set up techniques discussed above for tool holders 18 and 30, this being true regardless of the type of tool holder involved and whether is held double or triple tools, other types of drilling devices or boring tools.